Most inkjet inks currently available are low viscosity liquids which contain large amounts of water, often 90 weight percent or greater. The use of water as a solvent in these inks is advantageous because it is inexpensive, environmentally friendly and non-toxic. Unfortunately, water also has a relatively high boiling point and a high latent heat of evaporation. For this reason, inkjet inks which contain large amounts of water tend to be slow-drying. Slow-drying inks are disfavored for many printing applications because they lead to slow printing rates.
To speed up the printing rate of water-based inkjet inks, printing equipment may employ external heating devices to speed up the evaporation of water from the inks. Unfortunately, external heating involves heating equipment which is often expensive and impractical. Another approach to increasing the drying rate of water-based inkjet inks is to generate heat internally within the inks by incorporating radiation susceptors into the ink formulations. These susceptors are activated by exposing them to radiation of a suitable frequency, causing them to generate heat within the ink and speeding up the evaporation of water and other volatile solvents. Most of these susceptors are microwave activated inorganic salts. Unfortunately, the use of microwave energy poses human safety hazards in an inkjet printing device and also results in slow heating of the inks.
Inkjet ink formulations that optimize the transfer of radiation to an inkjet ink frequently do not provide inkjet inks with optimal printing properties. This problem is exacerbated by the standard practice in the printing industry of formulating and selling microwave activatable inkjet inks that are not tailored to specific printing applications or printing equipment and is further exacerbated by the standard practice of using microware sources that are insufficiently adjustable to allow their microwave parameters to be tailored based on the susceptibility characteristics of a selected inkjet ink.
Thus, a need exists for methods which provide improved drying times for inkjet inks while minimizing human safety hazards. In addition, a need exists for methods of providing a system for customizing inkjet inks based on pre-selected printing applications and printing equipment and a system for customizing a radiation source for use with a pre-selected radiation-activatable inkjet ink in a pre-selected printing application.